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de28dc9a04
Both plannable queries and utility commands are now always executed within Portals, which have been revamped so that they can handle the load (they used to be good only for single SELECT queries). Restructure code to push command-completion-tag selection logic out of postgres.c, so that it won't have to be duplicated between simple and extended queries. initdb forced due to addition of a field to Query nodes.
135 lines
4.5 KiB
C
135 lines
4.5 KiB
C
/*-------------------------------------------------------------------------
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*
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* memutils.h
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* This file contains declarations for memory allocation utility
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* functions. These are functions that are not quite widely used
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* enough to justify going in utils/palloc.h, but are still part
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* of the API of the memory management subsystem.
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*
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*
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: memutils.h,v 1.51 2003/05/02 20:54:36 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef MEMUTILS_H
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#define MEMUTILS_H
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#include "nodes/memnodes.h"
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/*
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* MaxAllocSize
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* Quasi-arbitrary limit on size of allocations.
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*
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* Note:
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* There is no guarantee that allocations smaller than MaxAllocSize
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* will succeed. Allocation requests larger than MaxAllocSize will
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* be summarily denied.
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*
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* XXX This is deliberately chosen to correspond to the limiting size
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* of varlena objects under TOAST. See VARATT_MASK_SIZE in postgres.h.
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*/
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#define MaxAllocSize ((Size) 0x3fffffff) /* 1 gigabyte - 1 */
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#define AllocSizeIsValid(size) (0 < (size) && (size) <= MaxAllocSize)
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/*
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* All chunks allocated by any memory context manager are required to be
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* preceded by a StandardChunkHeader at a spacing of STANDARDCHUNKHEADERSIZE.
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* A currently-allocated chunk must contain a backpointer to its owning
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* context as well as the allocated size of the chunk. The backpointer is
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* used by pfree() and repalloc() to find the context to call. The allocated
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* size is not absolutely essential, but it's expected to be needed by any
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* reasonable implementation.
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*/
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typedef struct StandardChunkHeader
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{
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MemoryContext context; /* owning context */
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Size size; /* size of data space allocated in chunk */
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#ifdef MEMORY_CONTEXT_CHECKING
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/* when debugging memory usage, also store actual requested size */
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Size requested_size;
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#endif
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} StandardChunkHeader;
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#define STANDARDCHUNKHEADERSIZE MAXALIGN(sizeof(StandardChunkHeader))
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/*
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* Standard top-level memory contexts.
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*
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* Only TopMemoryContext and ErrorContext are initialized by
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* MemoryContextInit() itself.
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*/
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extern DLLIMPORT MemoryContext TopMemoryContext;
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extern DLLIMPORT MemoryContext ErrorContext;
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extern DLLIMPORT MemoryContext PostmasterContext;
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extern DLLIMPORT MemoryContext CacheMemoryContext;
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extern DLLIMPORT MemoryContext MessageContext;
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extern DLLIMPORT MemoryContext TopTransactionContext;
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/* These two are transient links to contexts owned by other objects: */
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extern DLLIMPORT MemoryContext QueryContext;
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extern DLLIMPORT MemoryContext PortalContext;
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/*
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* Memory-context-type-independent functions in mcxt.c
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*/
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extern void MemoryContextInit(void);
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extern void MemoryContextReset(MemoryContext context);
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extern void MemoryContextDelete(MemoryContext context);
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extern void MemoryContextResetChildren(MemoryContext context);
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extern void MemoryContextDeleteChildren(MemoryContext context);
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extern void MemoryContextResetAndDeleteChildren(MemoryContext context);
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extern Size GetMemoryChunkSpace(void *pointer);
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extern MemoryContext GetMemoryChunkContext(void *pointer);
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extern void MemoryContextStats(MemoryContext context);
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#ifdef MEMORY_CONTEXT_CHECKING
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extern void MemoryContextCheck(MemoryContext context);
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#endif
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extern bool MemoryContextContains(MemoryContext context, void *pointer);
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/*
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* This routine handles the context-type-independent part of memory
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* context creation. It's intended to be called from context-type-
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* specific creation routines, and noplace else.
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*/
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extern MemoryContext MemoryContextCreate(NodeTag tag, Size size,
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MemoryContextMethods *methods,
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MemoryContext parent,
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const char *name);
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/*
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* Memory-context-type-specific functions
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*/
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/* aset.c */
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extern MemoryContext AllocSetContextCreate(MemoryContext parent,
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const char *name,
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Size minContextSize,
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Size initBlockSize,
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Size maxBlockSize);
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/*
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* Recommended default alloc parameters, suitable for "ordinary" contexts
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* that might hold quite a lot of data.
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*/
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#define ALLOCSET_DEFAULT_MINSIZE 0
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#define ALLOCSET_DEFAULT_INITSIZE (8 * 1024)
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#define ALLOCSET_DEFAULT_MAXSIZE (8 * 1024 * 1024)
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/*
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* Recommended alloc parameters for "small" contexts that are not expected
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* to contain much data (for example, a context to contain a query plan).
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*/
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#define ALLOCSET_SMALL_MINSIZE 0
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#define ALLOCSET_SMALL_INITSIZE (1 * 1024)
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#define ALLOCSET_SMALL_MAXSIZE (8 * 1024)
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#endif /* MEMUTILS_H */
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